The U.S. barred flights to Israel's main international airport outside Tel Aviv for at least 24 hours after a rocket from Gaza landed nearby, prompting Israel to angrily brand the ban a boon to Hamas's efforts to isolate the country.

Prime Minister Benjamin Netanyahu appealed to Secretary of State John Kerry to restore flights as the U.S. diplomat was in Cairo trying to broker a cease-fire between Israel and Hamas, the Islamist group...